I am writing to inform you I have already contacted my university and they agreed to reply in Arabic. I had to translate it myself and forward it to you. There could be more options, but this would be correct. Hope it helps!

Sara gave a helpful answer. I would change the sentences to identify what has been translated. I assume a school transcript of classes taken. For example: I am writing to inform you I have contacted my university and they sent me my transcript in Arabic. If your point is not that you have contacted the university but rather that you are providing a translated document, I suggest the following: (Dear Sir/Madam) I have received my transcript from my university. Please find attached the Arabic original and my translation. (update after comment by Eman) (if translated by someone else) I had the document translated into English. Attached is the original document, the translation, and the contact information for Mr. X, the translator. or Attached is the original document and the translation done by Mr. X, a professional translator. (if translated by the writer of the letter). I translated the document into English. Attached is the original document and the translation. or Attached is the original document and my translation.

No, there are many mistakes here.